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30톤 추력급 터보펌프 터빈의 구조 강도 및 진동 해석을 통한 안정성 예측
윤석환,전성민,이관호,김진한,Yoon, Suk-Hwan,Jeon, Seong-Min,Lee, Kwan-Ho,Kim, Jin-Han 한국유체기계학회 2004 한국유체기계학회 논문집 Vol.19 No.5
Static and dynamic structural analyses of a turbine bladed-disk for a liquid rocket turbopump are performed to investigate the safety level of strength and vibration at design point. During operation, turbopump is exposed to various external loads. Therefore, the effects of them should be carefully considered and properly modeled. First, due to the high rotational speed of the turbopump, effects of centrifugal forces are considered in the structural analysis. Thermal load caused by severe temperature differences is also considered. A three dimensional finite element method (FEM) is used for linear and nonlinear structural analyses with modified Newton-Raphson iteration method. After the nonlinear solution is obtained from the structural analysis, dynamic characteristics are obtained as a function of rotational speed from the linearized eigenvalue analysis at an equilibrium position. From the analysis results, characteristics of stress distribution and vibration were thoroughly examined and investigated.
윤석환(Suk-Hwan Yoon),전성민(Seong Min Jeon),김진한(Jinhan Kim) 한국추진공학회 2009 한국추진공학회 학술대회논문집 Vol.2009 No.11
75톤급 액체로켓엔진 터보펌프 조립체에 대한 열응력 해석을 수행하였다. 터보펌프 시스템의 거시적인 거동을 조사하기 위하여 전체 조립체를 해석 대상으로 고려하였으며 해석의 효율성을 높이기 위하여 2차원 축 대칭 모델로 해석하였다. 실제 운전 조건을 고려하여 예냉, 운전 및 운전 후 단계에 대한 열전달 조건을 상정하여 해석하였으며 각 단계에서의 온도 분포, 응력 분포 및 변형량을 예측하였다. 해석에는 터보펌프를 감싸고 있는 단열재의 영향 및 베어링에서 발생하는 발열량을 고려함으로써 최대한 정확한 예측이 가능하도록 하였다. A 75ton thrust turbopump system for liquid rocket engine was analyzed thermally and mechanically. A 2D axisymmetric model of the turbopump assembly was created. In the analysis operation cycle including chill-down, operation and post operation steps were considered. Appropriate heat transfer conditions for each step were modeled and applied. Transient temperature distribution was calculated, consequent mechanical analysis was conducted to predict stress and deformation. Effects of external heat insulators and heat dissipation at the bearings were considered in the heat transfer analysis.
윤석환(Suk-Hwan Yoon),전성민(Seong Min Jeon),김진한(Jinhan Kim) 한국추진공학회 2012 한국추진공학회지 Vol.16 No.5
Turbopump is a key component in liquid rocket engines, and reducing weight while maintaining structural safety is one of the major concerns of turbopump designers. To reduce the weight aluminium alloy castings instead of steel casings are introduced. The casting process is especially useful for enhancement of productivity and for reduction of product costs. But, since castings are used in space vehicle engines, reliability cannot be compromised. Therefore, proper design, production process and thorough investigation should be performed to ensure structural integrity. In this study inlet casings for a fuel pump were casted with A356.0-T6 alloy and using one of them a burst test was conducted to ensure structural integrity. Structural analysis is performed for simulation, and with multiple strain gages strains are measured and compared with predictions.
윤석환(Suk-Hwan Yoon),전성민(SeongMin Jeon),김진한(Jinhan Kim) 한국항공우주연구원 2006 항공우주기술 Vol.5 No.2
액체로켓엔진에서 연료와 산화제를 가압하는 역할을 하는 핵심부품인 터보펌프는 극저온 산화제와 구동 터빈의 고온 환경이 동일 축에 분포하고 있으며 내부 회전부 간극이 매우 작고 회전속도가 높아 기계적으로 대단히 열악한 환경에서 동작한다. 따라서 사고 위험도를 낮추기 위한 구조 해석 및 시험이 필수적인데, 본 연구에서는 특히 터보펌프 케이징의 구조해석 및 응력 측정이 이루어졌다. 기존의 단품 레벨에서의 해석에서 벗어나 연료펌프와 산화제펌프의 케이징 조립체 레벨에서 내압기밀시험 조건에 대한 구조해석이 이루어 졌으며 이를 통하여 케이징 간 체결효과 및 실 부분의 접촉 압력을 성공적으로 고려할 수 있었다. 또한, 연료펌프 케이징에 나타나는 높은 수준의 응력 집중 현상을 해석과 측정을 병행함으로써 성공적으로 예측하였다. The present paper describes transient thermal and mechanical analyses of a lox/kerosene type turbopump in a LRE(Liquid Rocket Engine). Turbopumps are used to pressurize propellants to achieve higher specific impulse of LRE. The turbopump under development has been designed and verified by structural analyses using finite element methods. Some parts of the turbopump operate under cryogenic environments, while the others work under ambient and high temperature environments. Therefore, numerical analysis at a turbopump system level is essential. In this study, casing assemblies of lox pump and fuel pump were analyzed to determine strength test and air-tightness test conditions. Also, some operational stress and strains of fuel pump casings were measured and analyzed. Based on these results, stress concentration of fuel pump casings during the operation could be successfully predicted.
윤석환(Suk-Hwan Yoon),전성민(Seong Min Jeon),김진한(Jinhan Kim) 한국추진공학회 2013 한국추진공학회지 Vol.17 No.6
Turbopump is typically an assembly of rotors and casings, and there are a number of joints between them. Every joint should be leak-proof, so there is always a seal to accomplish the goal. Among various seals, metal seals are advantageous in that they are robust at high pressure, and at wide range of temperature. In this study, flange joints using conical seal made of stainless steel, solid flat metal seal made of copper and metal C seal made of Inconel 718 were structurally designed and analyzed, considering both initial tightening and operating conditions.
반도체용 과산화수소 중 음이온 분석을 위한 헤드스페이스 고상마이크로 추출법을 활용한 기체크로마토그래피-질량분석법 개발
윤석환 ( Suk-hwan Yoon ),김현지 ( Hyun-ji Kim ),신호상 ( Ho-sang Shin ) 한국환경분석학회 2016 환경분석과 독성보건 Vol.19 No.3
An ultrasensitive method to detect trace anions (fluoride, nitrite and nitrate) in hydrogen peroxide (H2O2) for semiconductor by headspace solid phase microextraction (HS-SPME) gas chromatography mass spectrometry (GC-MS) was described. Fluoride, nitrite and nitrate in hydrogen peroxide reacted with pentafluorobenzyl bromide (PFB-Br) in a headspace vial and the formed PFB derivatives were vaporized and adsorbed onto a fiber. The optimal HS-SPME conditions were achieved with a 50/30 μm divinylbenzene-carboxen- polydimethylsiloxan (DVB-CAR-PDMS) fiber, 50 μL of PFB-Br (99%), 100 μL of 10% tetraoctylammonium bromide (10%) as a phase transfer catalyst, an extraction/derivatization temperature of 90oC, a heating time of 50 min, and a pH of 6.0. Under the established conditions, the method detection limits of fluoride, nitrite and nitrate were 2.8-4.0 μg/L in 30% H2O2 solutions (w/w) and the relative standard deviations were less than 4% at concentrations of 25 and 50 μg/L. The concentrations of anions in five concentrated H2O2 had detectable levels of 8.7 to 28.4 μg/L. The method was sensitive, reproducible and simple enough to permit the reliable routine analysis of anions in hydrogen peroxide for semiconductor.